The Relation between pH and Aquatic Animals

Abstract

1. The pH of a natural water is determined by the temperature, solids in solution and its carbon dioxide tension. 2. A change in the carbon dioxide tension of a water causes a definite and predictable change in pH, provided the carbon dioxide in solution is the only factor modifying the system. The amount of change in pH with a given change in carbon dioxide tension is determined by the water itself as a chemical system. That is, the pH at a definite carbon dioxide tension and temperature and the amount of change with a definite change in carbon dioxide tension are determined by the characteristics of the natural water itself. 3. Aquatic organisms are able to withstand wide ranges in pH. 4. Aquatic animals are affected in their physiological processes and behavior by changes in carbon dioxide and oxygen tensions. Of the two, a change in carbon dioxide tension is the more effective. 5. All aquatic animals can regulate their internal environment to bring them into harmony with their external environment. Th...